The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device having pixel electrodes and counter electrodes in a pixel region formed on a liquid-crystal-side surface of one substrate out of respective substrates which are arranged to face each other in an opposed manner with liquid crystal therebetween.
This kind of liquid crystal display device is referred to as a so-called lateral electric field type (IPS type) liquid crystal display device, for example, and is known as a display device which has a so-called wide viewing angle characteristic compared to liquid crystal display devices adopting other methods.
On the other hand, although the liquid crystal display device is usually provided with a backlight or the like on a back surface of a liquid crystal display panel, recently, in view of the reduction of the power consumption, there has been known a liquid crystal display device which allows the recognition of an image by making use of an external light such as sun beams when necessary.
The liquid crystal display device is of a type which forms a so-called transmission region which allows light from the backlight or the like to pass therethrough in a portion of the pixel region and forms a reflection region which reflects light from sun beams and returns the light frontward in a remaining portion. The latter liquid crystal display device is provided with a reflector or a means which has a function of the reflector.
Various types of liquid crystal display devices having such a constitution have been disclosed in JP-A-2003-207795 (patent document 1), JP-A-2003-15155 (patent document 2), JP-A-2001-343670 (patent document 3), JP-A-9-269508 (patent document 4) and the like. However, in the patent document 1, a distance between electrodes in the reflection region is narrower than a distance between electrodes in a transmission region and hence, the liquid crystal display device disclosed in the patent document 1 differs from the liquid crystal display device of the present invention.
Further, in the patent document 2, a potential from a second signal line electrode 11 is supplied to a reflector provided to the inside of a pixel (see FIG. 15 and FIG. 16 in the document) and hence, the liquid crystal display device disclosed in the patent document 2 differs from the liquid crystal display device of the present invention.
Further, in the patent document 3, although a potential of a video signal is supplied to a reflector which also functions as a capacitance, the patent document 3 is directed to a so-called vertical electric field type liquid crystal display device and hence, the liquid crystal display device disclosed in the patent document 3 differs from the liquid crystal display device of the present invention.
Still further, in the patent document 4, a pair of electrodes are respectively formed of a stacked body constituted of a non-light-transmitting conductive layer and a light-transmitting conductive layer. However, although the non-light-transmitting conductive layer is provided with a light shielding function, the non-light-transmitting conductive layer is not provided with a reflection function and hence, the liquid crystal display device disclosed in the patent document 4 differs from the liquid crystal display device of the present invention.